Pneumatic cutting-tool.



No. 691,334. Patents d Ian. l4, I902.

,J. W. BIRKENSTOGK.

PNEUMATlC CUTTING TOOL.

Application filed Ma 7, 1901.)

(No Model.)

m VENTOH A TTOBNEYS UNITED STATES PATENT OFFICE.

JOHN W. BIRKENSTOCK, OF NEW YORK, N. Y., ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO THE EMPIRE PNEUMATIC TOOL COMPANY OF THE STATE OF NEW YORK, OF NEW YORK, N. Y.

PNEUMATIC CUTTING-TOOL.

SPECIFICATION formingoart of Letters Patent No. 691,334, dated January 1902- Application filed May 7, 1901. Serial No. 59,140. (No model-J I To all whom it may concern.-

Beit known that 1, JOHN W. BIRKENSTOCK, a citizen of the United States, residing in New York, borough of Manhattan, in the State of New York, have invented certain new and useful Improvements in Pneumatic Cutting- 'lools,of which the following is a specification. This invention relates to an improvement in pneumatic cutting-tools to which reciproxo eating motion is' imparted in imitation of the motion imparted by a mallet, said cuttingtool being so constructed that the supply of compressed air can be instantlyinterrupted, so as to stop or start the tool as required; and r5 theinvention consists of a pneumatic cuttingtool comprising a cylinder, a reciprocating piston in said cylinder provided with a hammer, a handle attached to said cylinder and provided with a lever-operated valve for admitting air under pressure or shutting it off, a tubular slide-valve provided with abutments operated by the piston, ports for admitting air to the chambers at either end of the piston, and outlet-ports in the cylinder.

15 The invention consists, further, of certain In the accompanying drawings, Figure 1' 0 represents a side elevation of my improved pneumatic cutting-tool. Figs. 2 and 3 are vertical longitudinal sections of the same, showing the slide-valve in its primary and secondary positions, so as to illustrate the for- 5 ward-and-backward motion of the piston. Fig. 4; is a vertical transverse section on line 4 at, Fig. 3; and Fig. 5 is a detail section of the slide-valve operated by the piston.

Similar letterslof reference indicate corre- 0 sponding parts.

Referring to the drawings, A represents a cylindrical casing, which is closed at the rear end by a head B, provided with a suitable handle B. The bow-shaped handle is pro- 5 vided with a longitudinal recess, in which is arranged a fulcrumed lever C, which is provided with a thumb-piece or button 0 at its upper end for moving the lever in backward direction when it is desired to shut off the supply of compressed air or in the opposite 5o direction to admit air. The lower end of the bow-shaped handleis connected by a tubular channel B with the head B, said channel being controlled by means of a hollow slidevalve D, which is acted on by a knuckle C 5 on lever C, said valve having a port d, that may be placed in register with the inclined channel B when compressed air is to be supplied to the tool, but which at the outward movement of the lever is moved in upward 6o direction by the pressure action of the compressed air, so as to place the inlet-port clout of register with the inclined channel B when the supply of compressed air is to be interrupted. The lower tubularend of the handle His connected .by a suitable coupling e with the supply-pipe E for compressed air in the well-known manner. The opposite end of the cylindrical casing A is closed by a guide-disk a and provided with a projecting stationary 7o sleeve A, screwed into the head of the casing, as shown in Figs. 2 and 3. In the guidesleeveA is placed the polygonal shank of the cutting-tool T, the interior of the sleeve being made to fit to said shank, so as to guide the sameand prevent its axial turning. In the casing A is arranged an interior cylinder a, in thebore of which is guided a piston F, which is provided at the end adjacent to the tool-shank with a'hammer-like extension F, so as to strike the end of the tool-shank by the reciprocating motion of the piston. The air is admitted alternately into the opposite ends of the interior of the cylinder by means of a tubular sectional slide valve G, which is guided in'a bore a of the cylinder and head B, said slide-valve being inserted through the corresponding channel in the head, which is then closed by means of a screw-plug g. The slide-valve G is provided at opposite o ends with lugs 9, that project into the path of the piston, so as to be operated by the piston when it is moved in one or the opposite direction. Adjacent to the lugs g the tubular slide-valve G is provided with portspp 5 for the admission of compressed air, said ports communicating with channels a in the solid portion of the cylinder (1, which chanposite ends of the cylinder.

nels communicate with the spaces at the op- The outlet-ports are indicated by a a The cylinder is provided below the piston F with a recess R, in which is located an interiorly-threaded sleeve r, by which the two sections of the tubular slide-valve G are connected togetherand by which, owing to the difference in the threads otthe sections, the adjustment of the sections toward or away from each other is permitted. The polygonal head r at one end of the adj usting-sleeve '2" provides for the convenient adjustment of the same by means of a suitable wrench. By the adjustment of the sections of the slide-valve the lugs g are moved farther apart or closer together, whereby the stroke of the piston can be regulated within certain limits.

The operation of my improved hammer or cutting-tool is as follows: Thelever C is moved inwardly into the handle 13', so that the port (1 of the valve operated thereby is placed in linewiththeinclinedsupply-channelB The air under pressure then passes through one end of the tubular slide-valve G and through one portsay 19, Fig. 2--into the chamber located at one end of the piston F, so as to immediately force the piston forward and cause the same to strike by its hammer a blow on the shank of the tool T. By the forward motion of the piston the lug at the opposite end of the slide-valve is struck by the piston and the slide-valve shifted, so that the supply of air through the port p is interrupted, while the opposite port 19 is opened and air under pressure admitted into the annular chamber around the hammer F. The action of the air moves the piston back into its former position against the first lug, so as to shift the slide-valve back again into its initial position ready to receive the entire supply of compressed air at this end, which produces another forward stroke of the piston, and so on. As the piston abuts against the lugs, it never can fully move up to the ends of the cylinders, and hence the chambers at each end of the cylinders serve for cushioning the piston. The air in the cylinder is permitted to escape at the end of each stroke through the ports at a a arranged in the lower solid portion of the cylinder, one at each side of the slidevalve, said ports permitting the air to escape, so that no counteracting pressure is exerted on the piston during the return motion of the same.

When the motion of the tool is to be interrupted, by letting go of the lever in the handle the pressure of the air in tubular slidevalve D, which admits the air, will force the valve upward and lever backward, as shown in Fig. 1, so that the slide-valve D for the compressed air is-shifted and its port connection d with the inclined channel B interrupted, the motion of the tool being restored under the action of the compressed air as soon as the lever is returned into position in the handle, as shown in Figs. 2 and 3. By

'taking hold of thehandle the tool can be ap plied in any desired position to the work in hand, and thereby the cutting of stone and other work performed in a very quick and efiective manner. I

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. A pneumatic cutting-tool, consisting of a cylinder, a recessed handle suitably attached to said cylinder, a valve for admitting airunder pressure, a lever for operating said valve and located in the recess ot" said handle, a piston in the cylinder, provided with a hammer for actuating the tool, a tubular slide-valve provided with lugs projecting into the path of the piston, ports for supplying compressed air alternately to each end of the cylinder, and suitable outlet-ports, substantially as set forth.

2. A pneumatic cutting-tool, consisting of a cylinder, a box-shaped handle suitably applied to one end of the cylinder, a supplychannel in said handle, a controlling-valve, means for operating the said valve for admitting or shutting 0E the compressed air, a piston in said cylinder provided with ahaminer, a fixed sleeve for guiding the tool, a tubular slidevalve provided with lugs engaged by said piston, ports in saidslidevalve communicating with said supply-channel for admitting air into the ends of the cylinder, means for adjusting the tubular slide-valve, and outlet-portsin the cylinder,substantially as set forth.

In'testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

JOHN W. BIRKENSTOCK. 

